Generate NetworkSettings with IPC

This generates and applies NetworkSettings object with unix socket IPC.

- domain socket, json-rpc based communication
- switches to anyhow for burrow crate
- adds support for starting daemons on macos

Apple/NetworkExtension/libburrow/libburrow.h

@@ -1 +1,2 @@
-int retrieve();
+void start_srv();
+void initialize_oslog();